50 free USMLE step 1 questions and answers

In this USMLE step 1 test, we continue introduce to you the 9 tips for test day of the USMLE step 1 exam, with the look forward to helping you can pass your important exam.

50 free USMLE step 1 questions and answers. Image: Risealong.com

Of course, along with that we continue present to you the 50 free USMLE step 1 questions and answers on the Step 1 of the United States Medical Licensing Examination, which exam is sponsored by the Federation of State Medical Boards and the National Board of Medical Examiners – as a good way to help you prepare for your actual exam.

Nine tips for test day…

1. Arrive at the Prometric Test Center 30 minutes early so you are not rushed and have time to get organized.

You will be given a locker to store your personal items and then assigned a computer station. Remember that you have a total of seven hours to complete 350 questions, and a total of one hour to be used throughout the day for breaks and lunch.

2. To cope with fatigue, you will need to schedule breaks.

Our recommended schedule for the exam is:

Our recommended schedule for the exam

This allows you 10 minutes extra to use as needed. Remember that you will need to sign in and out when you take breaks. You should also be aware that if you leave the exam room during a block, it will be marked as an irregularity in your testing session. Therefore, you need to consider after each block whether you want to take a bathroom break.

3. Start with the beginning of the question block and work your way to the end.

The idea here is to get into a rhythm that will help create what one psychologist calls a “Flow” experience. The flow experience is a state of optimal concentration and maximal performance.

4. Do not skip any questions.

If you don’t know it when you come to it, you are not likely to know it later. Skipping around wastes time and can end up confusing you. Deal with each question as you come to it, answer it as best you can, and move on to the next question.

5. Limit your use of the marking feature to no more than two or three questions per block.

Of course you should answer each question as you come to it, but you may want to double-check yourself on a few questions. The marking feature lets you return to review and reconsider questions if you have time left over. Used correctly, marking will help you revisit questions where you have a high probability of getting the answer correct. Misused, marking causes you to not give a question your full attention the first time around. You simply may not have time to go back and look at questions you have marked, especially if you mark a lot of them.

6. Be cautious about changing answers.

In general, your odds of changing a correct answer to a wrong one are so much higher than the reverse that it is simply not worth the risk. If you change an answer, you are most likely making it wrong! Your first impulse is usually the correct one. Stay with it unless some clear insight occurs to you.

7. If you finish a question block with time left over, go back and “check” only those answers that you have previously marked.

Checking almost always leads to changing and tends to reduce your score. If you have a spare moment, make sure that you have entered an answer for every question in the block and then, relax. Sit, take a break, and mentally prepare yourself for the next block of questions. Focus on the questions to come, not the ones that are past.

8. Monitor your time.

Know how much you have left, so you do not find yourself rushed at the end. Work on your pacing from the beginning of the question block. Check your watch every 10 questions to make sure you are on the correct pace to finish. If you pace yourself throughout the block, you should not be squeezed for time at the end.

9. Relax.

During the breaks between question blocks, try to relax and not think back over the exam. The desire to recall questions is strong, but not helpful. Those questions are in the past; you will never see them again. Focus on relaxing and making the most of your break. Remember, you will always tend to remember those questions you get wrong.

50 free USMLE step 1 questions and answers

Take our 50 free USMLE step 1 questions in this USMLE step 1 practice test will help you review your knowledge, skill and strengths on the USMLE step 1 exam.

To respond the practice questions in this free USMLE step 1 practice test: Click the button corresponding to the best answer for each question.

When you complete the 25 free USMLE Step 1 questions in Section 1, click on the “Next” button at the bottom of the page to foward to Section 2 and continue to implement your USMLE practice test.

When you are finished, click the “Submit” button at the bottom of the Section 2’s page. Your browser window will reload, displaying your results.

50 Free USMLE Step 1 Practice Questions [Section 1]

The thrombolytic effect of tissue plasminogen activator depends on which of the following?

A. Circulating heparin

b. Concomitant therapy with high doses of aspirin

c. Factor II (prothrombin) concentration

d. Fibrinogen concentration

e. Presence of fibrin at the site of the thrombus

An 8-year-old boy has had a temperature of 38.8oC along with an upper respiratory tract infection over the past two days. His mother gives him medication to bring down his fever. Two days later, the boy becomes increasingly confused and lethargic, and starts vomiting heavily. Physical exam reveals a slightly enlarged and firm liver. His eyes are anicteric. Which of the following medications is likely responsible for this boy’s condition?

A. Acetaminophen

b. Acetylsalicylic acid

c. Ibuprofen

d. Indomethacin

e. Naproxen

Which of the following is a contraindication for usage of the drug cyclophosphamide?

A. Liver disease

b. Lung disease

c. Heart disease

d. Hypertension

e. Diabetes

A lacrosse player develops athlete's foot (tinea pedis). A drug with which the following mechanisms would be most effective for this patient?

A. Binding to hemagluttinin

b. Blockade of mycolic acid incorporation into cell wall

c. Inhibition of ergosterol synthesis

d. Inhibition of reverse transcriptase

e. Inhibition of transcription

A 22-year-old college student is brought to the emergency room by his parents because he's been behaving unusually for the last 6 months. His parents report he's been having frequent angry outbursts and tends to spend much more time alone in his room while at home. Upon questioning the patient reports that he has spent more time alone recently because the FBI is spying on him and he's not sure who he can trust. This patient could likely benefit from a medication that primarily acts on receptors for which ne

A. Acetylcholine

b. Dopamine

c. GABA

d. NMDA

e. Norepinephrine

Oral administration of grapefruit juice increases the bioavailability of a variety of drugs, including felodipine, midazolam, saquinavir, and verapamil. After oral administration of any one of these drugs, which of the following is most likely to be increased in the presence of grapefruit juice?

A. Hepatic CYP3A4 activity

b. Intestinal drug metabolism

c. Peak serum concentration

d. Total body clearance

e. Volume of distribution

Four drugs produce the same therapeutic effect by the same mechanism, but each has a unique toxicity. When used at a maximally effective therapeutic dose, the drug with which of the following sets of characteristics is most likely to have the highest incidence of toxicity?

A. Median Effective Dose 0.5x, Toxic Dose/Effective Dose 2.8

b. Median Effective Dose 1x, Toxic Dose/Effective Dose 2.1

c. Median Effective Dose 5x, Toxic Dose/Effective Dose 4.0

d. Median Effective Dose 33x, Toxic Dose/Effective Dose 3.0

e. N/A

A 45-year-old woman who is being treated for hypertension and hypercholesterolemia develops diffuse muscle pain and weakness. Her serum creatine kinase activity is increased. Which of the following drugs is most likely to have caused this clinical picture?

A. Captopril

b. Hydrochlorothiazide

c. Lovastatin

d. Nicotinic acid

e. Propranolol

32-year-old man is brought to the emergency department because of confusion, wheezing, vomiting, and diarrhea for the past 6 hours. He is sweating and salivating profusely. There is generalized muscle weakness. Which of the following substances is the most likely cause of these findings?

A. Glutethimide

b. Heroin

c. Jimson weed (belladonna alkaloids)

d. Parathion

e. Phencyclidine (PCP)

A 55-year-old woman with breast cancer develops shortness of breath and poor exercise tolerance while being treated with doxorubicin. Which of the following is the most likely cause of these symptoms?

A. Dilated cardiomyopathy

b. Obstructive pulmonary disease

c. Pulmonary hypertension

d. Restrictive cardiomyopathy

e. Restrictive pulmonary disease

A 12-year-old boy has a pruritic, coin-shaped, scaly erythematous lesion with a raised border and central clearing on his right arm. Potassium hydroxide preparation results are consistent with tinea corporis. A drug with which of the following mechanisms of action is most likely to be effective?

A. Blockade of ergosterol synthesis

b. Inhibition of DNA synthesis

c. Inhibition of ribosomal protein synthesis

d. Interference with mycolic acid synthesis

e. Irreversible binding to DNA-dependent RNA polymerase

An otherwise healthy 55-year-old Asian American man is given isoniazid and vitamin B6 (pyridoxine) after conversion of his PPD skin test. An x-ray of the chest shows no abnormalities. Four weeks later, he develops abdominal pain and jaundice. Which of the following is the most likely explanation?

A. Hepatic tuberculosis

b. Hepatitis B

c. Isoniazid-induced hepatitis

d. Pyridoxine-induced cholecystitis

e. Tuberculous pancreatitis

A 25-year-old professional cyclist is diagnosed with testicular cancer and undergoes chemotherapy. One month after beginning treatment, the patient complains of difficulty hearing. Which of the following chemotherapeutic agents is most likely responsible for this side effect?

A. Bleomycin

b. Busulfan

c. Cisplatin

d. Cytarabine

e. Doxorubicin

A 22-year-old college student presents to the ER complaining of difficulty speaking and the inability to swallow. He says he recently returned from spending Thanksgiving at his grandparents' house, and yesterday had eaten a family favorite, home-canned asparagus prepared by his grandmother. He denies other complaints and was in his usual state of excellent health before the onset of symptoms. Which of the following is the most appropriate treatment?

A. Administration of trivalent botulinum antitoxin

b. Administration of staphyloccocal enterotoxin antiserum

c. IV Amphotericin B

d. Immunization with s. aureus enterotoxin toxoid

e. PO ampicillin

A 30-year-old man with peptic ulcer disease suddenly develops pain, redness, and swelling of his right first metatarsophalangeal joint. There is no history of injury. Serum uric acid concentration is 8 mg/dL. Examination of joint aspirate shows birefringent crystals. Which of the following drugs is most appropriate to treat the acute symptoms in this patient?

A. Allopurinol

b. Colchicine

c. Morphine

d. Probenecid

e. Sulfinpyrazone

A 25-year-old man is started on clozapine for schizophrenia, paranoid type. He had been unsuccessfully treated for the past 2 months with haloperidol. The patient should be monitored for which of the following adverse effects?

A. Decreased erythrocyte count

b. Decreased leukocyte count

c. Decreased platelet count

d. Increased eosinophil count

e. Increased hemolysis

A 17 year old male has had numerous episodes of alternating stiffening and relaxing movements involving the entire body. On separate occasions, he was also noted to have episodes of staring blankly that last for about a minute. After prescribing the appropriate pharmacologic treatment, which of the following is most important to monitor as follow-up in this patient?

A. BUN and creatinine

b. Complete Blood Count (CBC)

c. Liver Function Tests (LFTs)

d. Pulmonary Function Tests (PFTs)

e. Serum electrolytes

A patient presents to your office complaining of a recent inability to have an orgasm when engaging in sexual activities with his wife. He recently started taking fluoxetine to control longstanding depression. Which of the following medications might you consider switching him to in order to best decrease his risk for sexual side effects?

A. mirtazapine

b. imipramine

c. bupropion

d. trazodone

e. citalopram

A 5-year-old boy with leukemia is treated with chemotherapy that includes ifosfamide. 48 hours after treatment, he presents with painless gross hematuria. What agent could have been given to prevent this side effect?

A. Allopurinol

b. Mesna

c. Misoprostol

d. Pralidoxime (2-PAM)

e. Thiosulfate

A 31-year-old man presents to the clinic for his yearly check-up and is found to have a blood pressure of 158/94. At a re-check two weeks later, his blood pressure is still elevated even though he has no risk factors for the development of hypertension. Further evaluation reveals a potassium level of 3.3 meq/L. Proper medical therapy for this man's most likely condition would involve which of the following mechanisms?

A. Agonism of the aldosterone receptor in the distal renal tubules

b. Antagonism of the aldosterone receptor in the distal renal tubules

c. Inhibition of sodium and chloride reabsorption in the ascending loop of Henle and distal renal tubule

d. Inhibition of sodium and water reabsorption in the proximal tubule and the loop of Henle

e. Inhibition of carbonic anhydrase activity

Looking in his medicine cabinet, a 45-year-old man with fever, nasal congestion, fatigue, and arthralgias finds a drug that was originally prescribed for his 15-year-old son's acne. He comes to see his doctor after noticing he has been urinating more frequently than normal ever since taking this drug. Physical examination reveals dry mucous membranes. Blood tests reveal hypokalemia and a pH of 7.2. Urinalysis reveals elevated levels of glucose, protein, calcium, and phosphate. If this condition goes untreat

A. Diabetes insipidus

b. Diabetes mellitus

c. Osteomalacia

d. Osteopetrosis

e. Rickets

A 60-year-old single male who has multiple sexual partners presents complaining of a painless chancre on his penis. His VDRL test returns a positive result. Administration of which of the following is most appropriate?

A. Amphotericin B

b. Azithromycin

c. Erythromycin

d. Penicillin G

e. Penicillin V

A 74-year-old man with urinary frequency and urgency has benign prostatic hyperplasia. He refuses operative intervention but agrees to a trial of finasteride therapy. During the trial, synthesis of which of the following substances is most likely to be inhibited?

A. Androstenedione

b. Dihydrotestosterone

c. Estradiol

d. Estrone

e. Testosterone

A 46-year-old man comes to the physician because of a 2-week history of intermittent dizziness and difficulty standing up. His symptoms began after he started treatment with sildenafil for erectile dysfunction. Physical examination shows no abnormalities. Which of the following is the most likely mechanism of action of sildenafil causing these adverse effects?

A. Decreased basal vascular smooth muscle tone

b. Decreased parasympathetic nerve activity

c. Decreased sympathetic nerve activity

d. Increased basal vascular smooth muscle tone

e. Increased parasympathetic nerve activity

A 72-year-old male presents to the physician complaining of waking up multiple times during the night to urinate and having trouble starting his stream. The patient reports that his health food store owner recommended that he try an herbal medication. Which of the following herbal agents did the health food store owner likely recommend to help this patient's condition?